Field of the Invention
The present invention relates to resolution enhancement on light field data including information about a direction and an intensity of a ray.
Description of the Related Art
A light field (light field is hereinafter referred to as LF) camera has been proposed. The LF camera is a camera that acquires information (LF data) about an incidence position, an incidence direction, and an intensity of a ray incident on the camera from an object. The LF camera includes an array camera in which a plurality of small cameras are arranged and a plenoptic camera in which a micro lens array, as a two dimensional array of a plurality of micro convex lenses, is disposed near an image sensor. With the LF camera, a plurality of images from different viewpoints (a group of parallax images) can be acquired at once. Disadvantageously, due to the mechanism, the resolution of each parallax image is generally lower than the resolution of an image acquired by a conventional camera with the same total number of pixels of the image sensor. Thus, a technique of enhancing resolution of the image that can be acquired by the LF camera has been required. US Patent Application Laid-Open No. 2013-0128087 discusses a technique of generating a high-resolution image by projecting LF data, corresponding to a point outside a plane corresponding to a single image, on the plane on an LF space defined by an incidence position and an incidence direction of a ray.
However, in the technique discussed in US patent application Laid-Open No. 2013-0128087, all pieces of the LF data are uniquely projected in the same direction. Thus, there is a problem in that a region in which resolution enhancement is achieved is limited to only a part of an image. This is because when the direction in which pieces of LF data corresponding to the same object are arranged in the LF space does not match the projection direction, an image of the object is spread by the projection and blurring occurs.